Process for producing shaped synthetic resin articles varying in shape of longitudinal section

Abstract

A shaped synthetic resin article varying in cross-sectional area and shape of longitudinal section along at least a part of the length is continuously produced by introducing a molten synthetic resin composition, extruded from an extruder die, between at least one pair of rolls rotating in the direction of extrusion so that the rolls of each pair contact each other on their periphery, the peripheral surfaces of the rolls being engraved so as to form a cavity corresponding to the shape of said shaped article when the rolls of each pair contact each other while being rotated, in which cavity the molten resin composition is remolded into an article having the desired shape and at the same time the surplus resin composition overflowing from said cavity is cut off by the edges of said rolls contacting each other, and then cooling the molded article to solidify the same. According to the above process, the diameter of the minimum cross-section of the article can be made much smaller than the outer diameter of the die or nozzle.

What is claimed is: 
     
       1. A process for the continuous production of a shaped synthetic resin article varying in cross-sectional area and in its shape of longitudinal cross section along at least a part of its length, which comprises extruding a molten polyethylene resin composition from an extruder die as an expanded polyethylene about a rope and between a pair of rolls rotating in the direction of extrusion so that the rolls of each pair contact each other on their periphery, the peripheral surfaces of the rolls being engraved so as to form a cavity into which the extrusion takes place and corresponding to the shape of said shaped article when the rolls contact each other while being rotated,   remolding in said cavity the expanded molten resin composition into an article having the desired shape, and at the same time, cutting off the surplus resin overflowing from said cavity by the edges of said cavity on the rolls, the edges of the cavity on one of the pair of rolls having a knife edge shape having an edge-width of 1 mm or less, and   then immediately quenching the thus molded article to solidify the same by blowing air or a mixture of air and water at 20° C or lower against the article.   
     
     
       2. A process according to claim 1, wherein the surplus resin remaining on the molded article which has not been cut off during the remolding in the cavity is removed by scraping with at least one pair of fine flexible metal rods which are located behind the rolls and can freely swing while being kept in contact with the surfaces of the molded article from which most of the surplus resin composition has been cut off. 
     
     
       3. A process according to claim 1, wherein a rope is covered with the extruded molten polyethylene resin composition at regular intervals.